package com.example.filter;

import com.alibaba.fastjson.JSONObject;
import com.example.pojo.Result;
import com.example.utils.JwtUtils;
import lombok.extern.slf4j.Slf4j;
import org.apache.catalina.connector.Request;
import org.springframework.util.StringUtils;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
//@WebFilter(urlPatterns = "/*")
public class LoginChecKFilter implements Filter {
    @Override //拦截到请求之后调用,调用多次
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {


        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse resp = (HttpServletResponse) servletResponse;
        //1.获取请求的url
        String url = req.getRequestURI();
        log.info("请求的url为: {}",url);

        //2.判断请求的url中是否包含login,如果包含说明是登录操作则放行
        if (url.contains("login")){
            log.info("请求为登录操作,放行");
            filterChain.doFilter(servletRequest,servletResponse);
            return;
        }

        //3.获取请求头中的令牌
        String jwt = req.getHeader("token");

        //4.判断令牌是否存在,如果不存在,返回错误结果(未登录)
        if (!StringUtils.hasLength(jwt)){
            log.info("请求头token为空,返回未登录错误信息");
            Result error = Result.error("NOT_LOGIN");
            String notlogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notlogin);
            return;
        }

        //5.解析token,如果解析失败,回错误结果(未登录)
        try {
            JwtUtils.ParseJwt(jwt);
        } catch (Exception e) {  //解析失败
            e.printStackTrace();
            log.info("解析令牌失败,返回未登录错误信息");
            Result error = Result.error("NOT_LOGIN");
            String notlogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notlogin);
            return;
        }
        //6.放行
        filterChain.doFilter(servletRequest, servletResponse);
    }

}
